A known waste storage device is described in UK Patent No. GB 2206094. The device includes a replaceable cassette having an inner, cylindrical core, an outer cylindrical wall and an annular base extending between the two. Layered or pleated tubular film is stored in the cassette and can be drawn over and through the hollow core. The end of the tubing is sealed to form a bag for receiving waste such as an infant's nappy or diaper inserted into the hollow core. The waste is held against rotation relative to the core by resilient fingers provided on the device such that when the core is subsequently rotated the flexible tubing forms a twist seal above the waste and the base of a subsequent bag for receiving further waste. As each item of waste is inserted, the preceding item is thrust down into a receptacle space below the cassette.
A cassette for use in such a device is described in GB 2221445. The cassette includes an annular cap placed over the stored tubing extending from the outer wall part way towards the core and floating on top of the tubing.
GB 2232951 relates to an apparatus for filling a cassette in which the empty cassette is placed on a mandrel, flexible tubing is fed onto the mandrel and compacted into the cassette by a compression ring and the floating annular cap is subsequently fitted in place.
The existing arrangements are highly satisfactory but because of the configuration of the cassette the material costs are high and disposal of an exhausted cassette can be difficult. Furthermore the manufacturing steps required are complex both to load the tubing into the annular space in the cassette and to fit the annular cap. Yet further the extent to which the flexible tubing can be compressed is limited in this configuration providing an attendant lower limit on the size of the cassette itself.
A further improvement to the devices discussed above is known from GB 2292725. This discloses, in addition, a funnel having a lower cylindrical portion and an upper outwardly flared portion. The cylindrical portion is an interference fit inside the top of the cylindrical core of the cassette. Tubing is drawn from the cassette around the funnel and down through the core providing a larger film surface and hence reducing the risk of unwanted soiling.
In practice, however, the funnel can be difficult to fit and can, for example, trap film. In addition the funnel needs to be retrieved and retained when an exhausted cassette is disposed of to be used with a subsequent cassette.